E:\>where ls
f:\Git\usr\bin\ls.exe

Mystery solved

Ok, getting past the dickish, completely unhelpful first part of your reply (as you can see in the comments, not EVERYONE was saying that), the second part helped me trace it back to this:

https://github.com/devkitPro/installer/releases

which is a toolset that I never intentionally installed, and was evidently added by an emulator package without me knowing where it was or what it did.

So thank you for (eventually) helping me find what it was, and now you and others know how to add it to cmd and don't have to complain about its absence.